Disconnect Required for Standby Generator?

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EZ Generator Switch said:
Why would any inspector not consider the breaker "Readily Accessible" located on the side of a generator? Think about this before you answer...Main panel in a house has a door covering the breakers...its readily accessible...but we place a door on a generator and its not the same? I think the OHJ should want to see the door as you approuch it not hide it around the back of the generator....it's just common sense. I would think that anyone having the skills & knowledge ...article 100 qualified person... If you have the skill & knowledge you should know there is a breaker behind that door just like on the panel.
There is no doubt in my mind the generator companies placed that breaker there as a means of service disconnect..not because they had some extra breakers laying around
IMO...I think AC units should have the same disconnect mounted with in the unit just like the generator has.
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That's fine as long as it meets 445.18 and 702.12

dSilanskas said:
If they want a disco outside at the generator. Can't you count the gas shut off at the generator as a disco? Kill the fuel kill the generator.
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Just what ever one would want, electricity going through your body while you wait for the gen. to run out of gas:happysad:
 
We should all stop looking at the language of the NEC for a moment and think about this logically. The circuit breaker protecting the generator output is located on the side of the unit itself. Obviously it disconnects all ungrounded conductors of the generator at that point. It is an acceptable disconnect means. It is located under a door that is capable of being locked. If the door is kept unlocked then it is readily accessible. If the customer chooses to lock that door then it's not readily accessible and a separate (unlocked) disconnect must be provided (not sure why someone would choose that option). The only other scenario I could think of where a separate disconnect would be required is if the generator was located say 50' or more from the building. Then a disconnect means would have to be located at the point of entry. In either case these disconnect means (in addition to the over-current protection) are intended to be used by authorized personnel in the event of an emergency and not necessarily by service personnel working on the unit.

Just my 2 cents worth.

Just thinking, if there were a fire in the bldg. and the FD shows up and wants to cut all power to the bldg, would they just shut the breaker off and leave the unit running on NG or LP:? If it's an automatic unit and they shut the gas off, it would sit there for a few minutes and then try continually to re-start until the "over-crank" feature shuts down the unit down completely
 
702.12 Outdoor Generator Sets.
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.
(Read only the underlined parts)


225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.


225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.


The disconnect located inside this generator does not fulfill the requirements of 702.12 as it is not within sight when the lid is closed.

The disconnect must meet the requirements of 225.36 in that it must be suitable as service equipment and disconnect all ungrounded conductors

The disconnect located inside a locked generator is readily accessible just like the service disconnect located in the panel in my basement which has a locked door and most other service disconnects throughout this great nation are located behind locked doors. What it does not meet is the within sight part due to being under a closed lid unless there is a window so that the disconnect is visible with the lid closed.

In the event that the disconnect on the generator is not within sight with the lid closed then one must be installed at the building that complies with Part II of Article 225.
702.12 states that even if the generator disconnect is visible and readily accessible it must comply with 225.36 and be suitable for service equipment. When I am in doubt of the rating of a disconnect as being ?suitable as service equipment? I generally look at Parts V, VI, and VII of 230 for a better understanding of suitable as service equipment.

dSilanskas said:
If they want a disco outside at the generator. Can't you count the gas shut off at the generator as a disco? Kill the fuel kill the generator.
Click to expand...
Yes this would be acceptable as long as the gas valve is suitable as service equipment, see 702.12

Why is a 200 amp transfer being installed on a 20KW generator? 20k/240=83 amps :?



 
jwelectric said:
702.12 Outdoor Generator Sets.
Why is a 200 amp transfer being installed on a 20KW generator? 20k/240=83 amps :?
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Probably because that's the way the mfr's are packaging them. Generac is selling 20K units with 100 or 200A service rated xfer switches.
 
jwelectric said:
702.12 Outdoor Generator Sets.
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.
(Read only the underlined parts)


225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.


225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.


The disconnect located inside this generator does not fulfill the requirements of 702.12 as it is not within sight when the lid is closed.

The disconnect must meet the requirements of 225.36 in that it must be suitable as service equipment and disconnect all ungrounded conductors

The disconnect located inside a locked generator is readily accessible just like the service disconnect located in the panel in my basement which has a locked door and most other service disconnects throughout this great nation are located behind locked doors. What it does not meet is the within sight part due to being under a closed lid unless there is a window so that the disconnect is visible with the lid closed.

In the event that the disconnect on the generator is not within sight with the lid closed then one must be installed at the building that complies with Part II of Article 225.
702.12 states that even if the generator disconnect is visible and readily accessible it must comply with 225.36 and be suitable for service equipment. When I am in doubt of the rating of a disconnect as being “suitable as service equipment” I generally look at Parts V, VI, and VII of 230 for a better understanding of suitable as service equipment.

Yes this would be acceptable as long as the gas valve is suitable as service equipment, see 702.12

Why is a 200 amp transfer being installed on a 20KW generator? 20k/240=83 amps :?



Click to expand...

Glad Mike jumped in on this. I will also add that the disconnect on the generator must also meet 445.18 and be lockable in the open position. Also, as Mike has pointed out, the disconnect must be service rated and by ULs standard if it is service rated it must be marked as such.
As far as another shut down the only thing I have ever seen was an extension of the E-stop circuit mounted beside the ATS inside of a building.

Also this
702.7 Signs.(A) Standby.​
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​
​
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A sign shall be placed at the service-entranceequipment that indicates the type and location of on-site optionalstandby power sources. A sign shall not be required for​
individual unit equipment for standby illumination.

And this

(B) Grounding.​
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​
​
Where removal of a grounding or bondingconnection in normal power source equipment interrupts thegrounding electrode conductor connection to the alternatepower source(s) grounded conductor, a warning sign shall beinstalled at the normal power source equipment stating:WARNINGSHOCK HAZARD EXISTS IF GROUNDINGELECTRODE CONDUCTOR OR BONDING JUMPERCONNECTION IN THIS EQUIPMENT IS REMOVED​
WHILE ALTERNATE SOURCE(S) IS ENERGIZED.
 
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B) Grounding.
Where removal of a grounding or bondingconnection in normal power source equipment interrupts thegrounding electrode conductor connection to the alternatepower source(s) grounded conductor, a warning sign shall beinstalled at the normal power source equipment stating:WARNINGSHOCK HAZARD EXISTS IF GROUNDINGELECTRODE CONDUCTOR OR BONDING JUMPERCONNECTION IN THIS EQUIPMENT IS REMOVED
WHILE ALTERNATE SOURCE(S) IS ENERGIZED

I'm trying to think of a reason / instance when you would disconnect a ground when the generator is running?
 
EZ Generator Switch said:
B) Grounding.
Where removal of a grounding or bondingconnection in normal power source equipment interrupts thegrounding electrode conductor connection to the alternatepower source(s) grounded conductor, a warning sign shall beinstalled at the normal power source equipment stating:WARNINGSHOCK HAZARD EXISTS IF GROUNDINGELECTRODE CONDUCTOR OR BONDING JUMPERCONNECTION IN THIS EQUIPMENT IS REMOVED
WHILE ALTERNATE SOURCE(S) IS ENERGIZED

I'm trying to think of a reason / instance when you would disconnect a ground when the generator is running?
Click to expand...

Only reason I can think of would be if some one was changing out the meter base:?:?
 
jwelectric said:
702.12 Outdoor Generator Sets.
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.
(Read only the underlined parts)


225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.


225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.


The disconnect located inside this generator does not fulfill the requirements of 702.12 as it is not within sight when the lid is closed.

The disconnect must meet the requirements of 225.36 in that it must be suitable as service equipment and disconnect all ungrounded conductors

The disconnect located inside a locked generator is readily accessible just like the service disconnect located in the panel in my basement which has a locked door and most other service disconnects throughout this great nation are located behind locked doors. What it does not meet is the within sight part due to being under a closed lid unless there is a window so that the disconnect is visible with the lid closed.

In the event that the disconnect on the generator is not within sight with the lid closed then one must be installed at the building that complies with Part II of Article 225.
702.12 states that even if the generator disconnect is visible and readily accessible it must comply with 225.36 and be suitable for service equipment. When I am in doubt of the rating of a disconnect as being ?suitable as service equipment? I generally look at Parts V, VI, and VII of 230 for a better understanding of suitable as service equipment.

Yes this would be acceptable as long as the gas valve is suitable as service equipment, see 702.12

Why is a 200 amp transfer being installed on a 20KW generator? 20k/240=83 amps :?


Click to expand...
Wow!! This may be a first, Mike. I fully agree with your comments.
 
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